Heating device



Feb. 11, 1941. H1. G'RAPP 2,231,445

HEATING DEVICE Filed Oct. 23, 1939 2 Sheets-Sheet l laf-30@- H. 1 GRAPPHEATING DEVICE Feb. 11, 1941.

Filed oct. 2s, 1939 2 sheets-sheet 2 VIwe?? or #falaz-:RTA 4F17?Patented Feb. 11, 1941 UNITED STATES p HEATING DEVICE Herbert L.- Grapp,Minneapolis, Minn. Application October 23, 1939, Serial No. 300,767

7 Claims.

This invention relates to a heating device or furnace for heating air.The heated air is delivered to different places and devices for use, onecommon use being for drying ovens where 5 various coated articles aredried.

In the type of device contemplated a heating chamber is provided withinwhich is a combustion chamber extending from one end of said heatingchamber. A fuel burner is disposed in said l combustion chamber adjacentsaid end and the combustion chamber has an open end intermediate theends of said heating chamber. Air

is usually withdrawn by a fan at the opposite end of said heatingchamber. It is necessary in the operation of the device to use fans ofdifferent capacity and to draw different volumes of air from the heatingchamber at different times. Such action has aiected the name of theburner and the combustion in the combustion chamber.

It has not been possible to get the uniform and desired temperatures inthe combustion chamber.

It is an object of this invention therefore to provide means comprisinga baille cooperating with said combustion chamber and movable toward andfrom the same to control the combustion.

It is a further object of the invention to provide a cup-shaped baillehaving its'open end directed toward the open end of said combustionchamber and preferably being coaxial therewith, together with means formoving said baffie and holding it at different distances from saidcombustion chamber.

These and other objects and advantages of the invention will be fullyset forth in the following description made in connection with theaccompany drawings in which like reference characters refer to similarparts throughout the several views and in which:

Fig. 1 is a view in side elevation of the device, some parts beingbroken away and others shown in vertical section;

Fig. 2 is a view in end elevation as seen from the right of Fig. 1, someparts being broken away and others shown in vertical section;

Fig. 3 is a"plan view of the device, certain parts being broken away andothers shown in .horizontal section; and i Fig. 4 is a vertical sectiontaken on line 4 4 of Fig. l as indicated by the arrows.

Referring to the drawings, a device is shown comprising a casing I0having therein a chamber Illa which forms a heating chamber. Whilecasing III might be of various forms, in the embodiment of the inventionillustrated it isl shown as of general cylindrical form. Casing IIlpreferably has spaced walls I0b between which is placed some refractorymaterial II such as heat resisting cement or fire brick. Casing II) atone end has an opening I 0c surrounded by a cylindrical 5 wall I0dprojecting some distance from the end of said casing and connecting witha fan or blower casing I2 having a discharge portion I2a. A fan I3 isillustrated as disposed in casing I2, being carried on a shaft I4journaled in a bear- 1| ing I5a of a spider bracket I5 secured to casingI2. Shaft I4 is also journaled in a bearing I6a of a flange bracket I6secured to the outer side of casing I2. A pulley I'I is secured to shaftI4 and illustrated as of the groove type. Pulley Il 1I will receive abelt driven from a suitable motor or other means for driving fan I3. Thedischarge portionv I2a of fan casing I2 will be connected by a suitableconduit to the place where the heated air is delivered. Casing I0 has anopen- 20 ing IIIe at one side and adjacent one end surrounded by a wallI0f which projects somewhat from the side of said casing. A damper orvalve I'Uo is disposed in casing IIJf manipulatable by a handle Ip.Casing I0 also has an opening IIlg 25 at one side shown -as opposite toopening Ille, which opening Illg is surrounded by a cylindrical casing I0h which projects some distance from the side of casing I0. A flatcircular damper or valve I8 is disposed in casing IIIh, the same be- 30ing carried on a shaft or pin I9 journaled in the sides of casing Illhand which has a handle 20 secured thereto at the upper side of casingIIlh. Casing I0 is illustrated as supported upon a frame 2| formed of aplate bent into semi- 35 circular shape at its top to receive andsupport casing I0, said plate having downwardly sloping portionsconnecting with vertical sides or portions 2Ia which are bent at theirterminals to form supporting flanges 2Ib resting on the sup- 40 portingsurface, Portions 2Ia are connected by spaced braces 22 adjacent theirends. Rods 23 are disposed adjacent each end and at each side of casingI0 and have flattened ends secured to the outer side of said casing inany suitable. 45 manner, as by welding. These rods extend through thedownwardly sloping portions of plate 2I and have threaded ends uponwhich are dis-` posed the nuts 24 at the inner side of plate 2l. Rods 23thus form braces or tie rodsfor holding 50 casing IIJ firmly in place.`Casing I0 is also provided with a comparatively small opening lili` atits top surrounded by a smallcylindrical projection or hub I 0i havingan aperture there,- through. A cover plate`25 overlies said opening 55and is connected to hub IM by a pivot member 26. Plate 25 can be swungabout pivot 26 to expose opening IIJi.

A combustion chamber 30a is provided disposed within heating chamberIlia. and while this combustion chamber might be variously formed, inthe embodiment of the invention illustrated it is shown as formed by acylindrical casing 30 shown as lined with some refractory material 3l,such as fire brick or heat resisting cement. Chamber 30a extends to oneend of heating chamber Ia and through the end thereof and has anextension or continuation 30h outside of casing I which is surrounded bya casing 32 which is also lined with refractory material 33 such as firebrick or some heat resisting cement. A fuel burner such as a gas or oilburner 34 is disposed in the end 30h of the combustion chamber and fuelis supplied to said burner by the usual conduit shown as 35. It will benoted that chamber 30a has an open end disposed intermediate the ends ofchamber Illa and substantially midway thereof. A bafe member 31 isprovided and while this might be of various forms, in the embodiment ofthe invention illustrated it is shown as cylindrical having a closed end31a and being open at the end opposite end 31a. Baiile 31 is thus ofcup-shape with its open side directed toward the open end of chamber 30aand it is illustrated as substantially coaxial with casing 38. 'Baiie 31is supported upon plates 38, having flanges extending along the outerside of said baille and secured thereto by rivets 39. Plates 38 increasein width toward their bottom edges, which edges rest upon the inner sideof inner casing Illb. A lug 40 is secured to the underside of baiile 31,centrally thereof, the same being of U-shape having downwardly extendingarms 40a and having a central portion engaging the outer side of baiiie31 and. secured thereto by rivets 4I. The arms 40a are apertured toreceive the threaded end of a rod 42. Nuts 43 are disposed on saidthreaded end, there being a nut at each side of each arm 40a. Rod 42extends longitudinally of chamber 30a and extends through the endthereof and through a flanged bracket 44.' Bracket 44 has outwardlyprojecting portions 44a oppositely disposed and having terminalprojections extending toward each other. A hand Wheel 45 is threaded onthe outer end of lrod 42 and provided with an annular groove 45a in thehub thereof, into which the terminal portions of members 44a, extend.The hub of hand wheel 45 thus engages the outer sides of members orportions 44a and the portion 45h of the hand wheel hub disposed inwardlyof the groove 45a engages the inner sides of said terminal parts of saidportions 44a. Hand wheel 45 is thus supported for rotation in bracket 44but cannot move longitudinally of rod 42. It will thus be seen thatturning ofhand wheel 45 will move rod 42 inwardly or outwardly.

In operation pulley I1 will be driven and fan I3 thus driven. Fuel willbe supplied through the conduit 35 to the burner 34. The outer end ofcasing 32 may be provided with a plurality of holes (not shown) whichmay be regulated by a movable or rotatable plate to admit any desiredamount of air about burner 34. With burner 34 operating the fuel, eithergas or oil, is burned in combustion chamber 30a. This chamber and thewalls thereof are raised to a very high temperature. Air will be drawninto heating chamber Illa through the openings Ie and IUg. Recirculatedair is usually drawn in through opening loe and through casing Ilif andthis can be regulated by the valve |00, Fresh air is drawn in throughopening I0g and casing Illh and this will be regulated by valve ordamper I8. This air passes around the highly heated combustion chamberand casing 30. The products of combustion issuing from combustionchamber 30a are prevented from beingdrawn directly out through the fancasing I2 by baiile 31. Baiiie 31 causes a movement of the gases towardthe end of the chamber opposite the fan and a good circulation of thesehot products of combustion and the entering air is secured. The positionof baille 31 is varied in relation to combustion chamber 30a accordingto the volume of air being drawn through the heater and the desiredtemperature. It has been found that by positioning baille 31 at acertain point for a certain volume of air the desired temperature can benicely secured in the combustion chamber and the air can be heated tothe desired point. The objectionable effect of the fan or blower on thecombustion chamber and the ame therein has been entirely eliminated.Baiile 31 can be readily moved to the desired point by turning handwheel 45 and it is securely held in the position to which it is moved.As stated baule 31 makes it possible to get the desired temperature incombustion chamber 30a and makes it possible to bring casing 30 anditslining 3I up to a desired uniform temperature. The provision of thebaille has therefore added greatly to the success of the device and tolthe attainment of the desired results. It is, of course, necessary thatthe baffle l31 be movable so that it can be positioned at the desiredpoint for the particular volume of air being handled and the temperaturedesired.

The device has been amply demonstrated in actual practice, found to bevery successful and eicient and is being commercially made.

It will, of course, be understood that various changes may be made inthe form, details, arrangement and proportions of the parts, withoutdeparting from the scope of applicants invention, which generallystated, consists in a device capable of carrying out the objects aboveset forth, in the parts and combinations of parts disclosed and definedin the appended claims.

What is claimed is:

1. A heating device having in combination, a heating chamber, a casinghaving a combustion ,chamber therein disposed within and surrounded bysaid heating chamber, a fuel burner at one end of said combustionchamber, the opposite end of said casing and chamber being open, meansfor drawing air from said heating chamber and a baille member extendingacross the open end of said casing and combustion chamber against whichthe products of combustion drawn from said combustion chamber engage andby which they are deected and means for positioning said baffle atdifferent distances from said open end of said combustion chamber.

2. A heating device having in combination, a heating chamber, a casinghaving a combustion chamber therein disposed within and surrounded bysaid heating chamber, a fuel burner at one end of said combustionchamber, the opposite end of said casing and chamber being open, meansfor drawing air from the end of said heating chamber adjacent the openend of said combustion chamber and a baiile member disposed between saidmeans and said open end and extending transversely of said open endagainst which the products of combustion drawn from said combustionchamber engage and means for moving said baille and positioning it atdiil'erent distances from the open end of said combustion chamber.

3. A heating device having in combination, a heating chamber, acombustion chamber within said heating chamber extending from one endthereof, said combustion chamber having an open end disposedsubstantially midway between the ends of said heating chamber, means forwithdrawing air from the other end of said heating chamber and acup-shaped baille having its open side directed toward the open end ofsaid combustion chamber and means for moving said bailie bodily towardand from said open end and for holding it in different positions tocontrol the movement of the products of combustion and the temperatureof said combustion chamber.

4.` A heating device having in combination, a heating chamber of generalcylindrical form, a combustion chamber of general cylindrical form ofmuch smaller diameter than said heating chamber extending from one endoi said heating charnber and having an open end disposed intermediatethe ends of said heating chamber, said combustion chamber being extendedbeyond said end of said heating chamber, a fuel burner disposed in saidcombustion chamber in said extended portion, means for withdrawing airfrom the opposite end of said heating chamber and a baille member ofcylindrical cup-shape coaxial with said combustion chamber having itsopen side directed toward the open end of said combustion chamber andmeans for moving said baille toward and from said open end. y

5. A heating device having in combination, a heating chamber, acombustion chamber extending from one end of said heating chamber withinthe same and of much smaller diameter than said heating chamber, saidcombustion chamber having an open end intermediate the ends of saidheating chamber, means for withdrawing air from said heating chamber, afuel burner disposed in said combustion chamber adjacent said irstmentioned end oi said heating chamber, a baille spaced from and disposedin alinement with said open end of said combustion chamber, meanssupporting said baille upon the wall of said heating chamber, a membersecured to said baiile and extending to a point without said heatingchamber and a member cooperating with said first mentioned member formoving said baille toward or away from said open end of said combustionchamber.

6. A heating device having in combination, a heating chamber'of generalcylindrical form, a combustion chamber of general cylindrical form andof much smaller diameter than said heating chamber extending from oneend of said heating chamber and having an open end disposed intermediatethe ends of said heating chamber, a fuel burner disposed in saidcombustion chamber adjacent said rst mentioned end oi.' said heatingchamber, means for withdrawing air from the opposite end of said heatingchamber, a baiile of circular form spaced from and substantially coaxialwith the open end of said combustion chamber, a bracket supporting saidbaille and slidable upon the bottom of said heating chamber, a rodsecured to said baille and projecting at the front oi' said heatingchamber and means cooperating with said rod to move said baile toward orfrom the open end o! said combustion chamber.

7. A heating device having in combination, a heating .chamber closed atits end save for a combustion chamber extending into one end and an airoutlet extending from its other end, means at the sides of said heatchamber for admitting air thereto, means for regulating the admission ofsaid air, said combustion chamber being of cylindrical form andprojecting into said heating chamber from one end to a pointintermediate the ends thereof, said combustion chamber having an openinner end, a fuel burner adjacent the other end of said combustionchamber, a baiile member disposed in said heating chamber spaced fromand centrally alined with the open end oi' said combustion chamber,means for positioning said balile member at different distances from theopen end of said combustion chamber and holding it in position, andmeans for withdrawing air through said air outlet.

HERBERT L. GRAPP.

